Prevalence of single-nucleotide variants in twenty-five pharmacogenes from a Cuban sample cohort.

Introduction: The Cuban population is genetically diverse, and information on the prevalence of genetic variants is still limited. As complex admixture processes have occurred, we hypothesized that the frequency of pharmacogenetic variants and drug responses may vary within the country. The aims of the study were to describe the frequency distribution of 43 single-nucleotide variants (SNVs) from 25 genes of pharmacogenetic interest within the Cuba population and in relation to other populations, while taking into consideration some descriptive variables such as place of birth and skin color. Materials and Methods: SNVs were analyzed in 357 unrelated healthy Cuban volunteers. Genotype, allele frequencies, and ancestry proportions were determined, and the pairwise fixation index (FST ) was evaluated. Results: Hardy-Weinberg equilibrium (HWE) deviations in six loci (rs11572103, rs2740574, rs776746, rs3025039, rs861539, and rs1762429) were identified. Minor allele frequencies (MAFs) ranged from 0.00 to 0.15 for variants in genes encoding xenobiotic metabolizing enzymes. They also ranged from 0.01 to 0.21 for variants in DNA repair, growth factors, methyltransferase, and methyl-binding proteins, while they ranged from 0.04 to 0.27 for variants in the O-6-methylguanine-DNA methyltransferase enzyme. Moderate genetic divergence was observed upon comparison to Africans (FST = 0.071 and SD 0.079), with 19 markers exhibiting moderate-to-large genetic differentiation. The average European, African, and Amerindian ancestry proportions were 67.8%, 27.2%, and 5.3%, respectively. Ancestry proportions differed by skin color and birthplace for both African and European components, with the exception of the European component, which showed no significant difference between individuals from Western and Eastern regions. Meanwhile, the statistical significance varied in comparisons by skin color and birthplace within the Amerindian component. Low genetic divergence was observed across geographical regions. We identified 12 variants showing moderate-to-large differentiation between White/Black individuals. Conclusion: Altogether, our results may support national strategies for the introduction of pharmacogenetic tools in clinical practice, contributing to the development of precision medicine in Cuba.

An updated examination of the perception of barriers for pharmacogenomics implementation and the usefulness of drug/gene pairs in Latin America and the Caribbean.

Pharmacogenomics (PGx) is considered an emergent field in developing countries. Research on PGx in the Latin American and the Caribbean (LAC) region remains scarce, with limited information in some populations. Thus, extrapolations are complicated, especially in mixed populations. In this paper, we reviewed and analyzed pharmacogenomic knowledge among the LAC scientific and clinical community and examined barriers to clinical application. We performed a search for publications and clinical trials in the field worldwide and evaluated the contribution of LAC. Next, we conducted a regional structured survey that evaluated a list of 14 potential barriers to the clinical implementation of biomarkers based on their importance. In addition, a paired list of 54 genes/drugs was analyzed to determine an association between biomarkers and response to genomic medicine. This survey was compared to a previous survey performed in 2014 to assess progress in the region. The search results indicated that Latin American and Caribbean countries have contributed 3.44% of the total publications and 2.45% of the PGx-related clinical trials worldwide thus far. A total of 106 professionals from 17 countries answered the survey. Six major groups of barriers were identified. Despite the region's continuous efforts in the last decade, the primary barrier to PGx implementation in LAC remains the same, the "need for guidelines, processes, and protocols for the clinical application of pharmacogenetics/pharmacogenomics". Cost-effectiveness issues are considered critical factors in the region. Items related to the reluctance of clinicians are currently less relevant. Based on the survey results, the highest ranked (96%-99%) gene/drug pairs perceived as important were CYP2D6/tamoxifen, CYP3A5/tacrolimus, CYP2D6/opioids, DPYD/fluoropyrimidines, TMPT/thiopurines, CYP2D6/tricyclic antidepressants, CYP2C19/tricyclic antidepressants, NUDT15/thiopurines, CYP2B6/efavirenz, and CYP2C19/clopidogrel. In conclusion, although the global contribution of LAC countries remains low in the PGx field, a relevant improvement has been observed in the region. The perception of the usefulness of PGx tests in biomedical community has drastically changed, raising awareness among physicians, which suggests a promising future in the clinical applications of PGx in LAC.

Ozonoterapia y cáncer: mito o realidad / Ozone Therapy and Cancer: Myth or Reality

Introducción: El uso clínico de la ozonoterapia se incrementa cada día. Abarca disímiles especialidades médicas como la oncología. En Cuba las investigaciones que evalúan el empleo de la ozonoterapia en pacientes con cáncer son escasas, se precisan estudios científicos que demuestren su eficacia clínica. Objetivo: Explicar los mecanismos farmacológicos y bioquímicos de la ozonoterapia y su uso en el cáncer como terapia complementaria. Métodos: Se consultaron bases de datos disponibles a través de la red de Infomed. Se utilizaron como palabras clave: cáncer, ozonoterapia y estrés oxidativo. Se seleccionaron artículos originales y de revisión sistemáticos de los últimos diez años que evaluaron la utilización de la ozonoterapia en el tratamiento del cáncer. Resultados: El cáncer es per se una enfermedad inductora de estrés oxidativo. La ozonoterapia respalda su utilización como una terapia adyuvante mediante el preacondicionamiento oxidativo que estimula los sistemas antioxidantes de la célula contra la acción de los radicales libres. Así, se logra neutralizar la acción nociva del estrés oxidativo. El ozono incrementa la eficacia de la radio - quimioterapia y ayuda a reducir los efectos secundarios de estos tratamientos al activar los sistemas antioxidantes de la célula. La ozonoterapia se caracteriza por la simplicidad de su aplicación, bajos costos, alta efectividad y prácticamente ausencia de efectos colaterales en comparación con otros tratamientos adyuvantes. Conclusiones: El uso de la ozonoterapia en oncología como una terapia adyuvante representó un recurso terapéutico de gran valor dado por su perfil de efectividad y seguridad. Su uso podría extenderse para disminuir los efectos secundarios y mejorar la calidad de vida de los pacientes(AU)

Introduction: The clinical use of ozone therapy is increasing every day worldwide and it covers different medical specialties, including oncology. However, in Cuba, the investigations that evaluate the use of ozone therapy in cancer patients are scarce, so scientific studies are needed to demonstrate its clinical efficacy. Objective: To explain the pharmacological and biochemical mechanisms of ozone therapy and its use in cancer as a complementary therapy. Methods: Databases available through Infomed Network were consulted. Key words used were cancer, ozone therapy and oxidative stress. Original and systematic review articles from the last ten years that evaluated the use of ozone therapy in the treatment of cancer were selected. Results: Cancer is, as such, a disease that induces oxidative stress. Ozone therapy supports its use as an adjuvant therapy through oxidative pre-conditioning that stimulates the cell's antioxidant systems against the action of free radicals. Thus, it is possible to neutralize the harmful action of oxidative stress. Ozone increases the efficacy of radio-chemotherapy and helps reducing the side effects of these treatments by activating the cell's antioxidant systems. Ozone therapy is characterized by the simplicity of its application, low costs, high effectiveness and with practically no side effects, compared to other adjuvant treatments. Conclusions: The use of ozone therapy in oncology as an adjuvant therapy represented a therapeutic resource of great value given its effectiveness and safety profile. Its use could be extended to improve tissue oxygenation and thus enhance the efficacy of radiochemotherapy, reducing side effects and improving the patients's quality of life(AU)

Polimorfismos en genes de reparación del daño al material genético y cáncer de pulmón

RESUMEN Introducción: El cáncer de pulmón es uno de los principales problemas de salud en Cuba y el mundo. Las diferencias genéticas a causa de polimorfismos de un solo nucleótido, son factores importantes involucrados en la susceptibilidad genética a esta enfermedad. En Cuba son escasos los datos disponibles sobre los polimorfismos de un solo nucleótido y su posible influencia sobre la aparición y pronóstico del cáncer. Objetivo: Exponer la importancia del estudio de los polimorfismos de un solo nucleótido en genes de la reparación del daño al ADN en el cáncer de pulmón. Desarrollo: El tabaquismo es el principal factor de riesgo para desarrollar cáncer de pulmón, sin embargo, aproximadamente el 15 % de los fumadores desarrollará la enfermedad. Los polimorfismos de un solo nucleótido son factores involucrados en la predisposición genética a las enfermedades. La presencia de variantes polimórficas puede modificar la eficacia de los sistemas de reparación, favoreciendo la aparición de genotoxicidad y/o mutagénesis. También pueden modificar la respuesta a los tratamientos oncológicos y la supervivencia de los pacientes. Por consiguiente, además de ser marcadores de susceptibilidad, los polimorfismos se consideran marcadores de pronóstico individual de respuesta a la terapia. Este trabajo enfatiza la utilidad de su evaluación como biomarcadores clínicos y de susceptibilidad genética a enfermedades en la población cubana. Conclusiones: El estudio de polimorfismos de un solo nucleótido permitirá el abordaje personalizado de enfermedades oncológicas, lo cual podría contribuir a su detección temprana y a definir grupos de individuos con alto riesgo de padecer cáncer de pulmón.

ABSTRACT Introduction: Lung cancer is one of the main health problems in Cuba and worldwide. Genetic differences due to single nucleotide polymorphisms are important factors involved in the genetic susceptibility to this disease. In Cuba, there are scarce data available on single nucleotide polymorphisms and their possible influence on the incidence and prognosis of cancer. Objective: To expose the importance of the study of single nucleotide polymorphisms in DNA damage repair genes in lung cancer. Results: Smoking is the main risk factor for developing lung cancer, however, approximately 15 % of smokers will develop the disease. Single nucleotide polymorphisms are important factors involved in genetic predisposition to diseases. The presence of polymorphic variants can modify the efficacy of repair systems, favoring the occurrence of genotoxicity and/or mutagenesis. They can also modify the response to oncological treatments and patient´s survival. Therefore, in addition to being susceptibility markers, polymorphisms are considered individual prognostic markers of response to therapy. This work emphasizes the usefulness of evaluating single nucleotide polymorphisms as clinical and susceptibility biomarkers in the Cuban population. Conclusions. The study of single nucleotide polymorphisms will allow a personalized approach to oncological diseases, which could contribute to define groups of individuals at high risk of getting lung cancer, therefore, early disease detection.